This invention relates to a longwall conveyor and plough guide assembly.
A longwall conveyor, such as a scraper-chain conveyor, conventionally comprises a plurality of conveyor sections joined end-to-end. At its face side, the conveyor is provided with a guide for a winning plough, the guide comprising a plurality of guide sections positioned end-to-end. Each guide section is associated with, and extends substantially along, a corresponding one of the conveyor sections. The conveyor sections are joined together in such a manner as to permit limited articulation therebetween in any direction. Each guide section has a generally L-shaped guide plate and a ramp-like cover plate which define therebetween upper and lower chain ducts for the plough drive chain.
When using a conveyor and guide assembly of this type, there is a danger of small pieces of coal (or other mineral material) finding their way through gaps between adjacent guide sections and into the chain ducts. If this does occur, the free passage of the plough drive chain is not guaranteed, which can lead to jamming. The upper chain duct is particularly susceptible to this danger, especially where the mine working is inclined. Thus, in inclined workings, many of the guide sections are pulled away from one another because of their weight, so that the gaps therebetween increase in size, which naturally promotes the penetration of small pieces of coal. In this connection, the upper chain duct is again more susceptible, since the plough directs won coal in the zone of the upper chain duct. However, when the assembly is used in horizontal (or slightly inclined) workings, the upper chain duct is mainly exposed to the danger of blockage caused by small pieces of coal which force their way in through gaps on the goaf side of the assembly.
The aim of the invention is to provide a conveyor and guide assembly which does not suffer from the disadvantage of coal entry into the upper chain duct.